1   package org.apache.lucene.store.db;
    2   
    3   /**
    4    * Licensed to the Apache Software Foundation (ASF) under one or more
    5    * contributor license agreements.  See the NOTICE file distributed with
    6    * this work for additional information regarding copyright ownership.
    7    * The ASF licenses this file to You under the Apache License, Version 2.0
    8    * (the "License"); you may not use this file except in compliance with
    9    * the License.  You may obtain a copy of the License at
   10    *
   11    *     http://www.apache.org/licenses/LICENSE-2.0
   12    *
   13    * Unless required by applicable law or agreed to in writing, software
   14    * distributed under the License is distributed on an "AS IS" BASIS,
   15    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   16    * See the License for the specific language governing permissions and
   17    * limitations under the License.
   18    */
   19   
   20   import java.io.IOException;
   21   
   22   import com.sleepycat.db.DatabaseEntry;
   23   import com.sleepycat.db.internal.Db;
   24   import com.sleepycat.db.internal.DbTxn;
   25   import com.sleepycat.db.DatabaseException;
   26   
   27   
   28   
   29   public class Block extends Object {
   30       protected DatabaseEntry key, data;
   31   
   32       protected Block(File file)
   33           throws IOException
   34       {
   35           byte[] fileKey = file.getKey();
   36   
   37           key = new DatabaseEntry(new byte[fileKey.length + 8]);
   38           key.setUserBuffer(fileKey.length + 8, true);
   39   
   40           data = new DatabaseEntry(new byte[DbIndexOutput.BLOCK_LEN]);
   41           data.setUserBuffer(data.getSize(), true);
   42   
   43           System.arraycopy(fileKey, 0, key.getData(), 0, fileKey.length);
   44           seek(0L);
   45       }
   46   
   47       protected byte[] getKey()
   48       {
   49           return key.getData();
   50       }
   51   
   52       protected byte[] getData()
   53       {
   54           return data.getData();
   55       }
   56   
   57       protected void seek(long position)
   58           throws IOException
   59       {
   60           byte[] data = key.getData();
   61           int index = data.length - 8;
   62   
   63           position >>>= DbIndexOutput.BLOCK_SHIFT;
   64   
   65           data[index + 0] = (byte) (0xff & (position >>> 56));
   66           data[index + 1] = (byte) (0xff & (position >>> 48));
   67           data[index + 2] = (byte) (0xff & (position >>> 40));
   68           data[index + 3] = (byte) (0xff & (position >>> 32));
   69           data[index + 4] = (byte) (0xff & (position >>> 24));
   70           data[index + 5] = (byte) (0xff & (position >>> 16));
   71           data[index + 6] = (byte) (0xff & (position >>>  8));
   72           data[index + 7] = (byte) (0xff & (position >>>  0));
   73       }
   74   
   75       protected void get(DbDirectory directory)
   76           throws IOException
   77       {
   78           try {
   79               directory.blocks.get(directory.txn, key, data, directory.flags);
   80           } catch (DatabaseException e) {
   81               throw new IOException(e.getMessage());
   82           }
   83       }
   84   
   85       protected void put(DbDirectory directory)
   86           throws IOException
   87       {
   88           try {
   89               directory.blocks.put(directory.txn, key, data, 0);
   90           } catch (DatabaseException e) {
   91               throw new IOException(e.getMessage());
   92           }
   93       }
   94   }